Jamie Scott, 38, and Gladys Scott, 35, have served 16 years of their terms.
Their mother, Evelyn Rasco, 64, of Pensacola, said Thursday she began caring for her daughters’ five children, as well as several grandchildren, after the sisters were incarcerated.
The time line for their release is unclear.
Mississippi Department of Corrections Commissioner Chris Epps said such releases to other states can take up to 45 days.
The sisters, who were imprisoned for a 1993 robbery that netted $11, would not have been eligible for parole until 2014.
Rasco talked to her daughters Thursday morning.
“They’re happy, they’re real happy, after 16 years of being away from their children,” Rasco said.
Barbour’s decision to suspend the sentences was applauded by civil rights organizations, who have long said the sentences were too harsh for the crime. The sisters are black, and their case has been a cause celebre in the state’s African-American communities.
Rasco said she, too, has been fighting for her daughters’ release for many years. She found out from a reporter Wednesday that her dream had come true.
“I was driving, and I had to pull over to the side of the road,” she said. “I got real hysterical. I had to thank God that this had finally come to a head.”
Barbour’s official involvement in the Scott sisters’ case began in September when he met with their supporters.
At trial, the sisters pleaded not guilty as accessories but were convicted of armed robbery, while three male accomplices received lesser sentences and since have been released.
In September, hundreds of people protested at the state Capitol in support of their release, while the NAACP, the Freedom Riders and others have petitioned Barbour.
While many have taken issue with the apparent severity of their punishment, Barbour also noted the cost to the state to keep them in prison.
Jamie Scott requires regular dialysis, and her sister has offered to donate a kidney to her.
“Their incarceration is no longer necessary for public safety or rehabilitation, and Jamie Scott’s medical condition creates a substantial cost to the state of Mississippi,” Barbour said in a statement.
Officials estimated that Jamie Scott’s dialysis treatments cost Mississippi about $200,000 a year.
Barbour’s order stands on the condition that Gladys donates one of her kidneys to her ailing sister, “a procedure which should be scheduled with urgency.”